From 175b69f301ec10b50a664e7560bdc0dc1bf0a4ab Mon Sep 17 00:00:00 2001
From: Vaclav Hausenblas <vaclav.hausenblas@gmail.com>
Date: Fri, 1 Feb 2019 16:18:59 +0100
Subject: [PATCH] adds functions for reading excel sheets and writing them as
 csv into a destination folder

---
 R/excel.R                      | 71 ++++++++++++++++++++++++++++++++++
 man/excel_worksheets.Rd        | 19 +++++++++
 man/excel_worksheets_readxl.Rd | 14 +++++++
 man/worksheets_to_csvs.Rd      | 18 +++++++++
 4 files changed, 122 insertions(+)
 create mode 100644 R/excel.R
 create mode 100644 man/excel_worksheets.Rd
 create mode 100644 man/excel_worksheets_readxl.Rd
 create mode 100644 man/worksheets_to_csvs.Rd

diff --git a/R/excel.R b/R/excel.R
new file mode 100644
index 0000000..2c0b87e
--- /dev/null
+++ b/R/excel.R
@@ -0,0 +1,71 @@
+#' Reads all sheets from an excel xlsx file into a list
+#'
+#' @param file file name
+#' @param ... args passed to openxlsx::readWorkbook
+#'
+#' @return a list of data.frames
+#' @export
+excel_worksheets <- function(file, ...) {
+  
+  if (!requireNamespace("openxlsx")) stop("openxlsx package required!")
+  
+  wb <- openxlsx::loadWorkbook(file)
+  sh_names <- openxlsx::sheets(wb)
+  
+  sheets <- 
+    lapply(
+      X   = sh_names, 
+      FUN = openxlsx::readWorkbook, 
+      # arguments passed to readWorkbook
+      xlsxFile = wb, 
+      ...
+    )
+  names(sheets) <- sh_names
+  
+  return(sheets)
+}
+
+
+#' Reads all sheets from an excel xlsx file into a list
+#'
+#' @param file file name
+#'
+#' @export
+excel_worksheets_readxl <- function(file) {
+  
+  if (!requireNamespace("readxl"))   stop("readxl package required!")
+  sh_names <- readxl::excel_sheets(path = file)
+  
+  sheets <- lapply(sh_names, readxl::read_xlsx, path = file, col_types = "text")
+  names(sheets) <- sh_names
+
+  return(sheets)
+}
+
+
+#' Writes list of data.frames as csv files into a folder
+#'
+#' @param sheets a list of data.frames
+#' @param path path to a destination dir
+#' @param ... args passed to fwrite
+#' @export
+worksheets_to_csvs <- function(sheets, path, ...) {
+  if (!requireNamespace("data.table")) stop("data.table package required!")
+  stopifnot(is.list(sheets))
+  
+  sh_names <- names(sheets)
+  if (is.null(sh_names)) sh_names <- seq_along(sheets)
+    
+  invisible(
+    sapply(sh_names, 
+           function(s) {
+             if (!is.null(sheets[[s]])) {
+               data.table::fwrite(
+                 x    = sheets[[s]],
+                 file = file.path(path, paste0(s, ".csv")), 
+                 ...)
+             }
+         })
+  )
+  
+}
diff --git a/man/excel_worksheets.Rd b/man/excel_worksheets.Rd
new file mode 100644
index 0000000..b8ac592
--- /dev/null
+++ b/man/excel_worksheets.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/excel.R
+\name{excel_worksheets}
+\alias{excel_worksheets}
+\title{Reads all sheets from an excel xlsx file into a list}
+\usage{
+excel_worksheets(file, ...)
+}
+\arguments{
+\item{file}{file name}
+
+\item{...}{args passed to openxlsx::readWorkbook}
+}
+\value{
+a list of data.frames
+}
+\description{
+Reads all sheets from an excel xlsx file into a list
+}
diff --git a/man/excel_worksheets_readxl.Rd b/man/excel_worksheets_readxl.Rd
new file mode 100644
index 0000000..d0130be
--- /dev/null
+++ b/man/excel_worksheets_readxl.Rd
@@ -0,0 +1,14 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/excel.R
+\name{excel_worksheets_readxl}
+\alias{excel_worksheets_readxl}
+\title{Reads all sheets from an excel xlsx file into a list}
+\usage{
+excel_worksheets_readxl(file)
+}
+\arguments{
+\item{file}{file name}
+}
+\description{
+Reads all sheets from an excel xlsx file into a list
+}
diff --git a/man/worksheets_to_csvs.Rd b/man/worksheets_to_csvs.Rd
new file mode 100644
index 0000000..ecf5d5a
--- /dev/null
+++ b/man/worksheets_to_csvs.Rd
@@ -0,0 +1,18 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/excel.R
+\name{worksheets_to_csvs}
+\alias{worksheets_to_csvs}
+\title{Writes list of data.frames as csv files into a folder}
+\usage{
+worksheets_to_csvs(sheets, path, ...)
+}
+\arguments{
+\item{sheets}{a list of data.frames}
+
+\item{path}{path to a destination dir}
+
+\item{...}{args passed to fwrite}
+}
+\description{
+Writes list of data.frames as csv files into a folder
+}